This invention relates to terminal board structures for dynamoelectric machines, and in particular to a terminal board structure having an integrally formed insulated pocket for selective reception of a motor lead. While the invention is described with particular reference to its application with single phase induction motors, those skilled in the art will recognize the wider applicability of the inventive principles disclosed hereinafter.
As will be appreciated by those skilled in the art, a number of dynamoelectric machines, for example, capacitor start and split phase induction motors, utilize a first winding combination for the starting conditions of motor operation, and a second winding combination for the run condition of motor operation. It is conventional to employ a centrifugal actuator in these motor types which operates a switch mechanism for connecting or disconnecting a source of electrical energy to various motor winding circuit configurations as motor speed varies. A number of switch assemblies are known in the prior art. A switch assembly with which the invention disclosed hereinafter is particularly suitable is described in the U.S. Pat. to Crow et al, No. 4,034,173, issued July 5, 1977. In Crow et al, a switch operated by a conventional centrifugal actuator is formed as a portion of a terminal board structure. Details of the switch, centrifugal actuator, and motor not disclosed herein are intended to be incorporated by reference to the Crow et al, U.S. Pat. No. 4,034,173.
In general, it is desirable to employ the terminal board and switch structure disclosed in Crow et al with as wide a range of motor constructions as possible. Frequently, the switches are employed with dual voltage motors. A dual voltage motor capability commonly is obtained by altering the interconnections of the motor windings. In dual voltage applications where motors are rated at 115/230 volts, for example, an extra lead is present at the terminal board when the motor is connected for high voltage operation. In the past, the extra lead was insulated through any convenient expedient including common electrically insulative tape and left untethered at the terminal board. The hand insulating procedure required by previously available alternatives is inherently expensive, and the degree of electrical insulation provided often is a matter of conjecture.
The invention disclosed hereinafter overcomes the time consuming hand insulating procedure previously employed and ensures that the motor lead is properly insulated by providing an insulating pocket integrally formed with the terminal board structure. The extra lead available with high voltage motor operation is inserted in that pocket when necessary.
One of the objects of this invention is to provide a terminal board structure having an insulating pocket associated with it.
Another object of this invention is to provide an insulating pocket and terminal board structure in which the insulating pocket is designed to lock a motor lead in position.
Another object of this invention is to provide a safe electrically insulated structure for reception of a motor lead.
Other objects of this invention will be apparent to those skilled in the art in light of the following description and accompanying drawing.